This invention is directed to an elastic-powered shrink laminate including a stretched elastic layer bonded to a heat shrinkable layer.
Personal care absorbent articles, such as training pants, adult incontinence articles, swimwear and some diapers, advantageously include a waistband that shrinks when heated. In one example, a waistband may include an elastic layer laminated between two nonwoven facing layers when the elastic layer is in a stretched state. For reasons relating to equipment and processing, the waistband remains in a substantially flat, extended state during manufacture of the absorbent article. Once the garment has been formed, the waistband is heated to cause shrinkage of the waistband. When the waistband shrinks, it pulls in the other materials to which it is laminated, enabling the absorbent article to properly and comfortably fit the wearer.
In the past, it has been difficult to provide waistband materials which have both heat shrinkage and significant elastic properties. If a material is elastic, it tends to recover to a dimensionally stable, retracted state at ambient temperature, and tends not to retract further upon heating. If a material is heat shrinkable, it tends to a) remain in a dimensionally unstable stretched state prior to heating, b) retract to a dimensionally stable unstretched state only after heating, and c) behave as an inelastic material at its dimensionally stable state after retraction and cooling. While polymer combinations have been developed to provide both elasticity and heat shrinkage, the properties tend to oppose each other such that greater elasticity coincides with insufficient heat shrinkage, and greater heat shrinkage coincides with insufficient elasticity. There is a need or desire for a better hybrid material that exhibits sufficient elasticity and heat shrinkage, for use in waistbands of personal care absorbent articles.